The present invention relates generally to apparatus for securing a wheel rim to a hub and more particularly to an assembly that permits rapid mounting and dismounting of a wheel rim to or from a wheel hub including at least one threaded stud.
In the field of vehicles, and particularly racing vehicles, the time required to mount or dismount a wheel from a hub can be very important. With regard to racing cars, where fractions of seconds spent changing wheels can determine the outcome of a race, it is imperative that no time be wasted in the process of mounting and dismounting wheels.
Generally, a wheel hub includes at least one threaded stud that extends generally perpendicularly from the wheel rim, parallel to the ground. The wheel rim defines at least one aperture of a size adapted to slidingly receive the threaded stud. After the rim has been placed in position adjacent to the wheel hub, with the threaded stud extending through the aperture defined in the wheel rim, a lug nut is then threadably engaged with the threaded stud and rotated into contact with the wheel rim, securing the rim to the hub.
In order to eliminate any time wasted in locating and orienting lug nuts for threading onto threaded studs, various efforts have been made to ensure that the lug nuts are appropriately positioned directly over the apertures in the rim prior to mounting a wheel upon a wheel hub. Glue and other adhesives have been used to attach the lug nuts to the rim. Unfortunately, though glue and other adhesives may be very inexpensive materials, temperature, moisture conditions and even rough handling can affect the effectiveness of the attachment, allowing the lug nut to separate from the rim unintentionally. The time spent searching for a separated lug nut can be quite costly in auto racing. Moreover, when such lug nuts are removed, there is nothing securing the lug nut to the rim. They may fall to the ground where they present a safety hazard to people walking around the site or may even be thrown over considerable distances at high rates of speed by a spinning tire. In addition, even if the lug nuts are retrieved without damage, time must be spent re-adhering the lugs for the next use.
If a lug nut is cross-threaded on a stud, it is at a minimum a nuisance and a waste of time because the lug nut must be reversed and re-threaded properly. In addition, if a lug nut is forced cross-thread with a wrench, the threads on the stud and/or the nut may be damaged and require replacement.
In response to the apparent deficiencies presented by the use of adhesives, various attempts have been made to provide apparatus for attaching the lug nuts to the wheel rim, such as the apparatus disclosed in U.S. Pat. No. 5,042,880 issued to Garuti et al. on Aug. 27, 1991. Therein is disclosed a coplanar spiral spring that is attached at one end to a wheel rim and a lug nut is rotatably mounted upon the spring. The spring retains the lug nut in a position adjacent to an aperture in the wheel rim to threadably engage a threaded stud as it passes through the aperture. While a substantial improvement over the attempts using adhesives, the ""880 apparatus is not a satisfactory solution to the conditions of auto racing.
The apparatus of the ""880 patent is designed to hold a lug nut in position adjacent to an aperture defined in the rim in precisely the position to matingly receive the threaded stud as it passes through the aperture without cross threading. However, if in the course of the normal rough and hurried handling of racing wheels the helical spring is bent, the ""880 apparatus will hold the nut in a position very likely to induce cross threading. Moreover, given the oily and dusty nature of auto racing, oil and dirt will accumulate on the threaded studs and lug nuts, thus also creating slight misalignments that can lead to cross threading.
Accordingly, one of the objects of the present invention is to provide a lug nut assembly that is secured to a wheel rim.
It is also an object of the present invention to provide a lug nut assembly that retains a lug nut in position adjacent to a wheel rim aperture in a position to matingly receive a threaded stud without cross threading.
It is a further object of the present invention to provide a lug nut assembly that protects a lug nut and threaded stud from accumulation of oil and dirt and from physical damage from raceway debris.
In accordance with the present invention a lug nut assembly is provided which retains a lug nut in an appropriate position to matingly engage a threaded stud as it passes through a wheel rim aperture without cross threading. The assembly includes an elongated sleeve that includes a central bore defining a longitudinal axis. The sleeve includes a secured end rotatably secured to the wheel rim and a distal end extending outwardly from the wheel rim. The sleeve includes at least one wrench engaging surface. A nut having a central threaded bore adapted to engage the threaded stud defines a central longitudinal axis that is coaxial with the axis of the sleeve. The nut is slidably mounted within the sleeve to move coaxially along the longitudinal axis of the sleeve. A longitudinal key that is parallel to the longitudinal axis of the sleeve prevents independent rotation of the sleeve relative to the nut. In one embodiment of the present invention a spring is located within the central bore of the sleeve to urge the nut towards the secured end of the sleeve and the distal end of the sleeve is closed with a cap to prevent entry of oil and particles into the central bore of the sleeve.